Core and surface temperature, live from the pour — differential and peak tracked against your limits, with the record your thermal control plan needs.
Embed temperature sensors in the concrete at critical locations before the pour.
PROTEST continuously records temperature data and tracks the core-to-surface differential against your thermal limits, in real time.
Clear reports and alerts flag differential limits early, with compliance documentation for your thermal control plan.
Most concrete monitoring is built to tell you when a temperature differential is climbing toward a risk threshold. That's genuinely useful — but it's a warning, not a fix. By the time a sensor is flagging the problem, the concrete already has the mix it was given, curing in the ground. Blankets, cooling pipes and changes to insulation can manage what's already in motion; they can't undo it.
The crack risk is set at the mix design stage — cement content and type, SCM replacement, water-cement ratio — long before the truck arrives on site. Get that right and there's less for a sensor to warn you about in the first place.
Watch temperature and differential rise, then respond with blankets, cooling pipes or an insulation change once the pour is already curing.
Model peak temperature and differential before the pour, and specify a mix — cement type, SCM content, w/c ratio — that keeps both inside safe limits from the start.
PROTEST's job is the monitoring — real temperature and differential data, alerts before limits are breached, and compliance records from the first pour.
Read on: Why temperature differentials crack concrete covers the two restraint mechanisms, what the mix design controls, and where the limits in CIRIA C766 and NSCS come from.
CONTEST is OTB Concrete's temperature and strength prediction software — early-age thermal analysis, differential predictions, thermal control plans and compliance reporting against specification limits. PROTEST is installed and managed as part of it.
How the thermal modelling works CONTEST — temperature & strength prediction at OTB ConcreteRugged, long-range, multi-channel transmitters send data straight to the PROTEST cloud — so site teams can see live data wherever they are, not just when they're standing next to the pour.
No handheld logger, no physical download. Readings arrive in the cloud continuously from the moment the sensors go in.
The questions that come up most often on mass pours and thermal control plans.
Normally two. A limiting core-to-surface differential, which controls surface cracking while the pour heats; and a peak temperature limit, which is about delayed ettringite formation rather than cracking at all.
There is no single correct differential figure — it's a function of the aggregate's coefficient of thermal expansion and tensile strain capacity, together with restraint and strength class. CIRIA C766 Table 7.1 tabulates values for common aggregates. See why temperature differentials crack concrete for how these are derived.
It's the NSCS default, applied as a single figure regardless of binder — but it's conservative rather than a fixed physical threshold.
C766 Appendix A8.3 reproduces guidance from Quillin (2001) banding delayed ettringite risk for Portland cement concretes: no risk below 60 °C, very low risk below 70 °C, low risk below 80 °C. The same source holds that fly ash above 20 % or GGBS above 40 % prevents DEF-induced expansion at peak temperatures up to 100 °C. NSCS doesn't build that distinction into its clause, so 65 °C applies unless the project agrees otherwise — but a higher project-specific limit on a GGBS or PFA mix, backed by that evidence, is a normal case to put to the design engineer.
Not by itself, and it's worth being straight about that. By the time a differential is climbing, the mix is already in the ground and the remaining controls are insulation, cooling and when you strike — real levers, but reactive ones that cost programme.
The preventive work happens at mix design: predicting peak and differential for the actual section and materials, then specifying a mix that holds both inside the limits. That's OTB's CONTEST service, with PROTEST installed as part of it to verify the prediction held.
At minimum, the hottest point of the core and the surface zone at around cover depth — the differential is only meaningful as a comparison between the two.
Which face matters more than people expect. The critical one is whichever is losing heat fastest: the exposed top surface overnight, the windward face, or the one struck first. A surface-zone sensor set too deep will under-read the differential and look perfectly healthy doing it.
A continuous temperature record showing the limits held, at what margin, and for how long — which is what closes out the thermal control plan.
Because collection is automatic, there are no gaps where somebody didn't walk the site that week. It's also the evidence base for whether the next pour's plan can be relaxed or needs tightening.
See PROTEST live with our engineers. We'll walk through a scenario tailored to your project type — no commitment required.
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A short session with one of our engineers, walked through a scenario for your project type.